Artificial tooth and crown.



J. KOHN.

ARTIFICIAL TOOTH AND GROWN.

APPLICATION FILED AUG. 16, 1910.

1,026,21 3. v Patented May 14,1912.

awe/Mom JOSEPH KOHN, OF PHILADELPHIA, PENNSYLVANIA.

ARTIFICIAL TOOTH AND CROWN.

Specification of Letters Patent.

Patented May 14, 1912.

Application filed August 16, 1910. Serial No. 577,457.

To all whom it may concern Be it known that I, JOSEPH KoHN, a citizen ofthe United States, residing in Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful Improvements in Artificial Teeth and Crowns; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to improvements in artificial teeth and crowns,being more especially the process of making and securing the pivot tothe tooth or crown.

In order to enable the dentist to secure an artificial tooth to a plateor to attach a crown to a root, the tooth or crown is generally providedwith pins or rivets fastened in the body of the tooth or crown. Incommon practice,these pins or rivets are made either of platinum, inwhich case they are baked into the tooth or crown, or they are made of acheaper metal soldered to a platinum anchorage which has been previouslybaked into the tooth or crown, the latter method being employed with aview to economizing in the use of platinum, which rare metal alone willsuccessfully withstand the heat required to bake the tooth or crown.

The object of my invention is to provide an improved form of anchorageto which a pivot or pin of suitable material may be firmly and securelyattached, after the tooth or crown is baked, and more readily and withgreater certainty that the solder has thoroughly united the pivot to theanchorage than is afforded by the methods now employed for this purpose;and in carrying out my said invention I employ a strip of platinumprovided with a flat portion, which forms one side of a cavity or socketprovided in the tooth or crown, and which cavity or socket I preferablymake of a shape that will provide a flat wall, such as halfround,triangular or square. The end of the platinum strip is provided with abend or corrugation, which is embedded in the tooth or crown, andprevents the pulling out of the strip, which is baked into the tooth orcrown. In combination with this construction the pin or pivot employedis shaped at its inner end to the form of the cavity or socket, with aflat surface which abuts against the platinum strip and to which it canbe readily soldered.

To more clearly illustrate my invention, attention is invited to theaccompanying drawings, in which- Figure 1 is a vertical centralsectional view through an artificial tooth embodying my invention. Fig.2 is a similar view minus the pivot. Fig. 3 is a top perspective view ofthe tooth; and Fig. 4 is a perspective view of the pivot.

Referring to the drawings: 1 designates an artificial tooth, made of theusual material and provided with a pivot receiving cavity 2 of ahalf-round or D-shaped form, which I prefer to use, and which has theflat wall 3, and the curved wall 4:.

When the tooth is baked, the strip 5, of platinum, is firmly held in thebody of the tooth, with its flat portion 6 resting against, and bakedto, the flat side 3 of the cavity, and its bent or corrugated portion 7embedded within the plastic body of the tooth. By this means, it will beseen that the strip cannot readily be pulled out of the teeth, evenshould the portion 6 become loose from the side 3. The flat portion 6 ofthe thin platinum strip is made to cover the entire depth of the flatside of the cavity, if the cavity is half-round, or on one side if it issquare or triangular.

The pivot or pin 8 consists of the body portion of usual shape, whilethe tooth engaging end is provided with the flat side 9, which is of thelength of the depth of the cavity or socket 2 of the tooth, the shoulder10 of the pin or pivot resting upon the upper portion of the toothexterior of the cavity, while the rounded portion 11 of the pivot or pinsnugly fits and abuts against the correspondingly curved wall 4 of thecavity. After the tooth, with the platinum strip embedded therein, isbaked, the pin or pivot is attached thereto by soldering the flat side 9of its tooth engaging end to the flat portion 6 of the platinum strip,thus insuring the locking of the pin or pivot of the tooth, while theirregular shape of the cavity and co-acting end of the pin or pivotinsures the latter against any turning movement.

By this construction, it will be readily seen that my invention has manyadvantages, namely: The proper union of the strip and pin is morecertain, as the solder does not have to travel to the bottom of thecavity to make the union, as is the case where a tube is used for theanchorage, and the union being visible the failure of the solder tounite properly can be readily detected before the tooth is secured tothe plate or the crown attached to the root; the cost is reduoed in viewof the fact that less platinum is employed; and the strength anddurability are increased as the whole length of the pivot'end is unitedto the strip, and the strip being baked with its bent or corrugated endwithin the body of the porcelain of the tooth will make a firmanchorage, and one less lia- 7 ing of the union.

What I claim, as new, is

1. An artificial tooth or crown comprising a body portion of plasticmaterial provided with a cavity of half-round shape in the top thereof,a strip of refractory metal embedded within the body of the tooth andbelow the surface of said cavity and extending up forming a metal wallalong the flat side of said cavity, and a pin of less refractory 2. Anartificial tooth or crown comprising a body portion of plastic materialprovided with a cavity having a flat side, a strip of refractory metalanchored within the body of the tooth and having a portion fittingagainst the fiat wall of the cavity, and a pin or pivot of lessrefractory metal having an end similar in shape to the cavity adapted tofit within the cavity and be secured to said strip, and provided with arecess fitting over said strip.

3. An artificial tooth or crown, comprising a body portion made of aplastic material, said body portion being provided with a cavity havinga fiat side, a strip of metal anchored and baked within the body andhaving a portion forming a fiat wall of the cavity and extendingslightly above the mouth of the cavity, and a pin or pivot having an endsimilar in shape to the cavity adapted to fit within the cavity, andprovided with a recess fitting over the projecting portion of the strip.

JOSEPH KOHN.

Witnesses ALEX. J. BRIAN, BELLE B. FRAME.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

